Step 2: Measuring ingredients and cooking them
This step determines whether you will have a soft, honey-and-milk candy or a solid mass that is impossible to cut.
Make sure there is enough water in the botton of the pot to wet it entirely. Without some water, your sugar will burn.
Measure your cane sugar, corn syrup, honey, butter, and vanilla into the pot. When you measure the syrup and honey, don't worry about the bit that stays on the measuring spoon. You will have enough of the syrup and honey without scraping it.
For measuring the butter, the paper wrapping should have tablespoons marked on it, so cut it there, or just scoop it with the spoon.
Now that all your ingredients are together, stir them together a bit. This should result in a bit of a slush. Clip on the candy thermometer.
You'll need a burner slightly smaller than the bottom of the pan. Turn the flame to a high-medium-ish setting. The slush will become liquid quickly, so stir frequently and check the temperature constantly. If you smell burning or see any darker colouring, turn the heat down, stir a whole lot, and hope that the sugar's still fine.
The mixture will bubble a lot. This is normal. The colour should be a very light caramel, like in the picture.
It takes about 3 minutes for the sugar to reach 250F (120C), but don't rely on the time. Watch the thermometer intently as the temperature rises. As soon as it reaches 250F (not 250C) turn the stove off. If the sugar reached 255F, don't panic, you might be fine. If the sugar reached 275F, you're probably going to have to start over and pay better attention.
(edit): Note on the temperature: if you live at high altitude, you will need to adjust to 38F above the local boiling point of water. To find this, stick the thermometer in a pot of boiling water. Thanks to the commenters who reminded me of this.